You can find a list of systems that run on ARM processors on Wikipedia. There are 23 Linux distributions and a few other Unix-like systems.

But many of them are not intended to run on mobiles, so after installation (if you manage to install it) you may encounter many problems like lack of drivers for almost everything (touchscreen, modem, wifi, etc).

ALTLinux community has been working on an ARM port of ALTLinux (and the Sisyphus package repository) (description in Russian): ARMv5 variant, and ARMv7 (hard-float).

ALTLinux infrastructure for building packages is convenient for such a task, because ALTLinux Team has taken care of constantly checking that the Sisyphus package repository can be correctly rebuilt automatically.